There are a wide variety of structural members or structural panels presently being made of a relatively light-gauge sheet metal. This material has comparatively high strength for its thickness and can be shaped into a variety of cross sections using various techniques such as stamping devices, presses, continuous cold roll-forming apparatus and the like. Shaped structural members have been found to be particularly useful in the construction of utility buildings and like structures. Shaped sheet metal structural members heretofore provided have frequently taken the form of a channel or trough having a bottom and opposed sidewalls and an outer opening. Such a channel-shaped structure made of sheet metal is readily cold roll-formed and is readily connected side by side by using side flanges.
The use of shaped sheet metal structures or panels has been greatly enhanced by recent developments and improved practices in utilizing relatively lightweight, portable, roll-forming apparatus that is taken to the job site and is used to form continuous, one-piece, generally channel-shaped structural panels. In constructing a building or like structure these panels are first rolled into the required shape and cut to the required length, assembled side by side, and then are connected together along a continuous seam using a highly efficient seamforming device. The individual panels formed by the abovedescribed apparatus may be generally characterized by having a generally channel-shaped configuration with a connecting flange at the outer free end of one side wall turned laterally into the channel opening and another connecting flange at the outer free end of the other sidewall that turns laterally away from the channel opening, and these flanges are used to connect the panels side by side at a continuous seam without the use of bolts or third element connectors.
The forming apparatus has a curving section that curves a straight formed panel into a shape that is substantially semicircular along its length and this curved or arched free-span panel forms both the top and sides of the building without additional support. The straight-shaped panels are used to close the ends of the building. The details of the panel and assembly practices are described more fully in my U.S. Pat. Nos. 3,875,642, 3,842,627, 3,902,288 and 3,967,430.
Among the advantages of this approach to forming structural panels and constructing buildings and like structures are that the panels may be continuously formed and cut to the precise length required at the job site, the greater efficiency in shipping relatively compact coil stock to the job site and storing same at the job site until used, and the fact that these continuous one-piece panels provide relatively wide, free-span structures that do not require additional structural support.
In the construction of buildings using the abovedescribed free-span, arched panels there are, however, special circumstances and certain applications in which additional strength may be required and applications in which heat insulation is desirable or required.
Accordingly, it is an object of the present invention to provide a novel cap for covering a generally channel-shaped panel or shaped structure which interconnects therewith in such a way as to greatly increase the structural strength of the composite structure over that of the panel alone.
Another object of the present invention is to provide a novel cap for a generally channel-shaped panel that provides a composite structure closed on all sides that is capable of being effectively heat-insulated.
Another object of the present invention is to provide a novel composite structure comprised of a generally channel-shaped panel and a cap covering and secured to the panel, the composite structure being heat-insulated so as to eliminate all metal-to-metal contact between the cap and panel.
Still a further object of the present invention is to provide a novel cap for shaped panels such as building panels characterized by a longitudinal, continuous, one-piece body having opposed side edge portions that are readily formed as a unitary construction from sheet metal in a continuous, cold roll-forming operation and are readily fastened securely to assembled shaped panels so as to remain in place and form a composite structure that is considerably stronger than the connected shaped panels alone.
Yet another object of the present invention is to provide a novel structural cap for a generally channel-shaped structural panel having oppositely disposed edge portions that cover and strengthen oppositely disposed connecting side flanges of the panel and are supported in place by a generally channel-shaped intermediate body portion that inserts into and resists deformation of the sidewalls of the structural panel under loads.